1. University of Malaya Centre for Ionic Liquids, University of Malaya, Kuala Lumpur 50603, Malaysia
2. Department of Chemical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia
3. Nanotechnology and Catalysis Research Centre (NANOCAT), University of Malaya, Kuala Lumpur 50603, Malaysia
4. Department of Civil Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia